26 THE GROUSE SUBFAMILY 



the female retains what answers to the supernuptial dress of the 

 male a whole month longer eight months as against seven; while 

 similarly she wears her "eclipse" plumage the "summer" breed- 

 ing plumage of Mr. Ogilvie-Grant a month less, April to July, or 

 four months as against five in the cock. 



These discrepancies depend, possibly, not so much on inherent 

 distinctions as on changes in the metabolism brought about by 

 internal parasites! That is to say, the incidence of disease falls 

 differently on the sexes : since during April and May large numbers 

 of cocks appear to fall victims to a parasitic worm, resulting in the 

 disease known as strongylosis. According to the statistics of the 

 recent Grouse Commission, about eight cocks to one hen succumb at 

 this season, possibly because exhausted by the intensity of the 

 courtship, while the female becomes more susceptible to disease after 

 the labours of egg-production and incubation ; but then her "eclipse " 

 or moult is accomplished. This explanation, however, is lacking in 

 cogency : another is needed. 



On this subject of the moulting and seasonal changes of 

 coloration in the red-grouse a few remarks yet remain to be made. 

 As to the order of the moult, Mr. Grant has pointed out that the 

 first feathers of what he terms the " winter," and what I have termed 

 the " supernuptial," moult begin to appear on the rump towards the 

 end of August or beginning of September, and from thence onwards 

 the renewal of the feathers spreads towards the head, which is the 

 last to change. The " eclipse " dress is assumed in the opposite order 

 the head and neck being the first to change. But the feathers of 

 the breast and abdomen, be it noted, are not moulted till the autumn, 

 when the "winter" or supernuptial dress is assumed. This fact is 

 one of considerable significance, marking, it would seem, the beginning 

 of the end of the " eclipse " dress the last phases of which are seen 

 in the capercaillie, blackcock, and partridge, wherein, as we have 

 already remarked, only the head and neck retain remnants of this 

 ancient dress. In June the feathers clothing the " legs " and toes 



